The spherical compressor technology is a new subject developed in recent years. The structure and the principle of the spherical compressor are completely different from those of the existing compressor. In the spherical compressor, a piston and a turntable which are arranged in a spherical inner cavity are driven by the rotation of a main shaft to make relative movement. A pair of or multiple pairs of working chambers continuously variable in volume are formed in the space to generate compression and expansion. The spherical compressor technology is greatly developed and widely used due to its increasing development and improvement in recent years. The spherical compressor has the advantages of no intake/exhaust valve, fewer movement parts, small vibration, high mechanical efficiency, reliability in sealing and the like. Its advantages in the field of micro compressors and high-compression-ratio pump-type machinery are more apparent. At present, the spherical compressor technology has already achieved multiple patents both in China and abroad; however, when the main shaft rotates to a position at which the turntable axis and the piston axis are superposed, a dead point of movement of the mechanism is generated, thereby easily resulting in locking and incapable rotation of the mechanism; and particularly under the working condition of small structural size, poor lubrication and high pressure ratio, the locking phenomenon is more apparent.
The specific reasons for the locking of a rotor are analyzed as follows:
Because the rotation of the piston is driven by an eccentric main shaft, when the main shaft rotates to a position at which the turntable axis and the piston axis are superposed, a resultant force generated by the main shaft on a turntable is perpendicularly intersected with the axes of the piston and the turntable, and the force generated by the main shaft on the turntable cannot generate the torque component driving the piston and the turntable to rotate along respective axes at this position and cannot drive the piston and the turntable to rotate. This is called the movement dead point of the mechanism. Analysis on the stress is as follows: the main shaft is driven by a motor to rotate, the main shaft generates a driving force on the turntable, and a component force of the driving force enables the piston and the turntable to rotate along respective axes; when the piston and the turntable rotate to a position nearby the position at which the axis of the turntable and the axis of the piston are superposed, the torque generated by the component force enabling the piston and the turntable to rotate is smaller and smaller until being zero; consequently, when the piston axis and the turntable axis are approximately superposed, the piston and the turntable cannot obtain sufficient torque to rotate along respective axes, so that the rotation of the piston and the turntable is locked nearby this position, and a movement dead point of the mechanism is generated; and when the movement dead point is at a starting state or the rotation is stopped at the state, the piston and the turntable cannot be started at next time.
The patent with the patent number of ZL201310100697.5 and the name of “a turntable rotation synchronizing mechanism for a spherical compressor” provides a technical solution: a turntable rotation synchronizing mechanism is arranged between a turntable spherical surface and a matched cylinder inner spherical surface, so that when the turntable rotates to the position at which the turntable axis and the piston axis are superposed, at the moment when the torque obtained by the turntable from the main shaft is zero, the torque generated by the synchronizing mechanism can still enable the turntable to move continuously; and therefore, the turntable is unlikely to lock, and the dead point problem of the movement of the spherical compressor mechanism is fundamentally solved. However, an adverse effect is that since the turntable synchronizing mechanism is arranged between the turntable spherical surface and the cylinder inner spherical surface, a concave slideway arranged on the matched spherical surfaces reduces the sealing area, and even becomes a gas leakage passage between the working chambers, so that the surface sealing advantage of the spherical compressor is alleviated, the spherical compressor cannot work under the working condition of the micro structure at high pressure, and the efficiency is decreased.